<template>
  <div class="child">
    <h3>我是Child组件（子组件）</h3>
    {{ sum }}
  </div>
</template>

<script>
import {ref} from "vue";

export default {
  name: "ChildCom",
  components: {},
  async setup() {
    let sum = ref(0)
    let p = new Promise((resolve) => {
      setTimeout(() => {
        resolve({sum})
      }, 3000)
    })

    return await p
  }
}
</script>

<style>
.child {
  background-color: skyblue;
  padding: 10px;
}
</style>
